Jim
09-27-2012, 08:25 PM
I've always been fascinated with super subsonic loads. So, I ran a test today with my H&R .223 rifle.
I loaded nine rounds of 55 gr. FMJs over Bullseye in decreasing loads. The highest load was 5.0 grains of Bullseye and each load was decreased by .5 grains. The lowest load was 1.0 grains.
I knew, sooner or later, I would stick a bullet, but I was prepared for that. I started at the 5.0 load and worked down. Believe it or not, the 1.5 gr. load actually pooted the bullet out of the barrel. The bullet over the 1.0 gr. load stuck. I got it out with no problem.
There's no way I can quantify the muzzle report except to give you my interpretation of the volume on a 1 to 10 scale. I shot this test with out plugs or muffs because I wanted to hear the report as it actually sounded.
Assigning a level of 10 to the 5 gr. load, the 4.5 and the 4.0 seemed to be right at 10. I couldn't tell any difference. All shots below that were audibly quieter. I would say the 3.5 was about 7 or 8. The 3.0 was about 5 or 6. The 2.5 was about 4 or so. The 2.0 was about 3. The 1.5 was barely audible and the 1.0 stuck in the barrel.
The next phase of this experiment is to start working back up, looking for the sweet spot. I intend to start at 3.0 and go up in .2 gr. increments. The ultimate goal is to see how little powder is required to get the bullets to group at 50 feet. Once I determine that, I'll switch powders and start all over again.
The powders I'm looking at are all relatively fast powders. Unique, Red Dot, 2400 & WC820. It will take me a while to get all this done, but at least I got it started. I'll report as I progress through each powder.
I loaded nine rounds of 55 gr. FMJs over Bullseye in decreasing loads. The highest load was 5.0 grains of Bullseye and each load was decreased by .5 grains. The lowest load was 1.0 grains.
I knew, sooner or later, I would stick a bullet, but I was prepared for that. I started at the 5.0 load and worked down. Believe it or not, the 1.5 gr. load actually pooted the bullet out of the barrel. The bullet over the 1.0 gr. load stuck. I got it out with no problem.
There's no way I can quantify the muzzle report except to give you my interpretation of the volume on a 1 to 10 scale. I shot this test with out plugs or muffs because I wanted to hear the report as it actually sounded.
Assigning a level of 10 to the 5 gr. load, the 4.5 and the 4.0 seemed to be right at 10. I couldn't tell any difference. All shots below that were audibly quieter. I would say the 3.5 was about 7 or 8. The 3.0 was about 5 or 6. The 2.5 was about 4 or so. The 2.0 was about 3. The 1.5 was barely audible and the 1.0 stuck in the barrel.
The next phase of this experiment is to start working back up, looking for the sweet spot. I intend to start at 3.0 and go up in .2 gr. increments. The ultimate goal is to see how little powder is required to get the bullets to group at 50 feet. Once I determine that, I'll switch powders and start all over again.
The powders I'm looking at are all relatively fast powders. Unique, Red Dot, 2400 & WC820. It will take me a while to get all this done, but at least I got it started. I'll report as I progress through each powder.